Issues with Imprecise Poly-Build Using SHP file

Question

Hello there!

I am having some issues bringing in a POLY shp file, generating polygons using Poly-Build, and then using Spatial Match to see if points fall within those polygons.

The main issue I am experiencing seems to be that Alteryx is not handling the shape file very precisely. Here is a comparison of how Tableau draws it vs Alteryx:

MA Senate Shape File in Tableau

Same shape file using Alteryx polybuild

I am having issues with Spatial Match due to the overlap. I understand this to be a side effect of using Convex Hull to build the polygon. However, it does not appear that the POLY file has a sequence column I can reference to draw it via lines.

Any idea how to get this working in Alteryx? Is there a preparation step I need to take prior to the poly-build?

The source files can be found here: http://wsgw.mass.gov/data/gispub/shape/state/senate2012.zip

Any help on this topic would be greatly appreciated.

Best,
Keith

NicoleJohnson · Accepted Answer

See attached - I think you can just bring the SHP file in as-is because it has the polygons for each district already included in the file data as a spatial object field, so no additional processing should be necessary to create the shapes for each district. If you add a Browse tool after the initial input data tool, you'll see that all the district pieces fit together to create that same shape you are seeing in Tableau. When you go to do your Spatial Match, feed the SHP file records into the Universe node while pointing your points to the Target input, and you should be able to find the polygon each point falls within...

Hope this helps :)

Cheers,

NJ